Sergey Sitnik

Prof. Sergey Sitnik

Chair of Applied Mathematics and Computer Modelling, Institute of Engineering and Digital Technologies, Belgorod State National Research University, 308015 Belgorod, Russia
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Research Focus & Metrics

Academic Career Length

27Years (2000-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 April 2010 in Journal of Mathematical Analysis and Applications
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Journal Article
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DKDmitrii Karp
Dmitrii Karp
Sergey SitnikSergey Sitnik
Sergey Sitnik

15 December 2018 in Contemporary Mathematics. Fundamental Directions
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VKValeriy V Katrakhov
Valeriy V Katrakhov
Sergey SitnikSergey Sitnik
Sergey Sitnik
КВКатрахов Валерий Вячеславович
Катрахов Валерий Вячеславович
The main content of this book is composed from two doctoral theses: by V. V. Katrakhov (1989) and by S. M. Sitnik (2016). In our work, for the first time in the format of a monograph, we systematically expound the theory of transmutation operators and their applications to differential equations with singularities in coefficients, in particular, with Bessel operators. Along with detailed survey and bibliography on this theory, the book contains original results of the authors. Significant part of these results is published with detailed proofs for the first time. In the first chapter, we give historical background, necessary notation, definitions, and auxiliary facts. In the second chapter, we give the detailed theory of Sonin and Poisson transmutations. In the third chapter, we describe an important special class of the Buschman-Erde´lyi transmutations and their applications. In the fourth chapter, we consider new weighted boundary-value problems with Sonin and Poisson transmutations. In the fifth chapter, we consider applications of the Buschman-Erde´lyi transmutations of special form to new boundary-value problems for elliptic equations with significant singularities of solutions. In the sixth chapter, we describe a universal compositional method for construction of transmutations and its applications. In the concluding seventh chapter, we consider applications of the theory of transmutations to differential equations with variable coefficients: namely, to the problem of construction of a new class of transmutations with sharp estimates of kernels for perturbed differential equations with the Bessel operator, and to special cases of the well-known Landis problem on exponential estimates of the rate of growth for solutions of the stationary Schro¨dinger equation. The book is concluded with a brief biographic essay about Valeriy V. Katrakhov, as well as detailed bibliography containing 648 references.

1 November 2009 in Journal of Approximation Theory
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DKDmitrii Karp
Dmitrii Karp
Sergey SitnikSergey Sitnik
Sergey Sitnik

1 June 2021 in Lobachevskii Journal of Mathematics
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DDDurdimurod Durdiev
Durdimurod Durdiev
Shishkina ElinaShishkina Elina
Shishkina Elina
Sergey SitnikSergey Sitnik
Sergey Sitnik
This paper intends on obtaining the explicit solution of \(n\)-dimensional anomalous diffusion equation in the infinite domain with non-zero initial condition and vanishing condition at infinity. It is shown that this equation can be derived from the parabolic integro-differential equation with memory in which the kernel is \(t^{-\alpha}E_{1-\alpha,1-\alpha}(-t^{1-\alpha})\), \(\alpha\in(0,1),\) where \(E_{\alpha,\beta}\) is the Mittag-Liffler function. Based on Laplace and Fourier transforms the properties of the Fox H-function and convolution theorem, explicit solution for anomalous diffusion equation is obtained.

27 June 2006 in Journal of Computational and Applied Mathematics
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DKDmitrii Karp
Dmitrii Karp
Sergey SitnikSergey Sitnik
Sergey Sitnik

10 December 2019 in Mathematics
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Shishkina ElinaShishkina Elina
Shishkina Elina
Sergey SitnikSergey Sitnik
Sergey Sitnik
In this article we propose and study a method to solve ordinary differential equations with left-sided fractional Bessel derivatives on semi-axes of Gerasimov–Caputo type. We derive explicit solutions to equations with fractional powers of the Bessel operator using the Meijer integral transform.